I have the same problem, however my app never was released for sale yet. still in the development phase and all of a sudden all previous releases are now expired. New versions deploy fine to TF, and shows up for users but they get the same "Could not install [app name]. The requested app is not available or doesn't exist."
My next try is to create a new app I guess.
dgocg
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution